1. Field of the Invention
The present invention relates to a method of vertically sealing off dumps to prevent the seepage of water therefrom, including the step of producing a sealing wall about the dump area which is to be sealed off; the present invention also relates to an arrangement for carrying out this method.
2. Description of the Prior Art
Dumps are indispensible for disposing of garbage, trash, refuse, and other nonusable materials. Only certain materials are allowed to be deposited in a given dump. The intent is to minimize the contamination of the ground and hence the impurities which could enter the ground water. However, due to the manner of collection, and the number of deposits, it is nevertheless impossible to completely avoid the dumping of materials which are contaminated with dangerous materials which are injurious to health. If these materials are water soluble, they are leached from the dump and pass into the ground water. This is, of course, to be avoided under all circumstances.
A horizontal seal (base seal) for dumps has already been proposed, with the effectiveness and reliability thereof being constantly controlled and improved. Guide lines are contained in a pamphlet of the National Council on Refuse entitled "The Systematic Disposition of Refuse". Proposals for vertically sealing off a dump are also known. In circular Nr. 17 of 8/83 of the firm Preussag AG, there is described a vertical sealing by means of a slotted sealing wall, according to which bentonite and plastic materials of bentonite, additives, cement, and water are listed as sealing material. A bentonite-cement suspension is utilized for a method developed in France. Possible leakage from the sealing wall is to be countered by lowering the level of the ground water in the dump. However, such a reduction of the level of the ground water is extremely expensive. Tests relating to the suitability and permeability of various sealing materials (bentonite mixtures) are disclosed in publications of Professor Simons, who holds the chair for Foundation Engineering and Soil Mechanics at the Technical University at Braunschweig. The water tightness or permeability achieved was, depending upon the mixture ratios and setting time, in the range of from k=10.sup.-11 (m/s) to 10.sup.-8 (m/s). The main problem of all of these heretofore known methods is the leakage of the sealing layers, which although it is relatively small, is nonetheless not insignificant. Not only the location but also the extent and the control of the leakage are therefore of very great interest.
An object of the present invention is to further improve a method of the aforementioned general type in such a way that any leakage which occurs can be detected and localized, and contaminated seepage water in the sealing wall can be determined in a controlled manner and the escape of the seepage water into the surrounding ground and ground water can be prevented.